/* @JUDGE_ID: 13160xx 900 C++ */
// 03/25/10 21:46:01

//@BEGIN_OF_SOURCE_CODE 

#include <iostream>

using namespace std;

int main()
{
	long long int fib[51] = {1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765,
	 10946, 17711, 28657, 46368, 75025, 121393, 196418, 317811, 514229, 832040, 1346269, 2178309, 
	 3524578, 5702887, 9227465, 14930352, 24157817, 39088169, 63245986,
	 102334155, 165580141, 267914296, 433494437, 701408733, 1134903170, 1836311903,
	 2971215073LL, 
	 4807526976LL, 7778742049LL, 12586269025LL, 20365011074LL };

	/*
	fib[0] = 1;
	fib[1] = 1;

	for(int i=2;i<51;i++) {
		fib[i] = fib[i-1] + fib[i-2];
		cout << fib[i] << ", ";
	}
	cout << endl;
	*/
		
	int n;
	while(1) {
		cin>>n;
		if(n==0) break;
		cout << fib[n] << endl;
	}

	return 0;
}

